## tab(selector, [options])
tab tab导航栏
**Kind**: global function
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| selector | string | | tab的selector |
| [options] | object | | 配置项 |
| [options.defaultIndex] | number | 0 | 初始展示的index |
| [options.onChange] | function | | 点击tab时，返回对应的index |
**Example**
#### html
```html
```
#### js
```javascript
weui.tab('#tab',{
defaultIndex: 0,
onChange: function(index){
console.log(index);
}
});
```